Improvement in self-centering punches



Unirse STATES PATENT @trici-'3,

SAML. Z. HALL, OF GAMDEN, ASSIGNOR TO HIMSELF AND GEORGE MOTT,

OF HOBOKEN,

NEW JERSEY.

IMPROVEMENT IN SELF-CENTERING PUNCHES.

Sg-eciralion forming l-art of Letters Patent No. 418,0l, dated May 30, 1F65; antcdatcd May 1G, 18135;

fo all whom t may concern,.-

Be it known that I, SAMUEL Z. HALL, of Camden, in the county of Camden and State of N ew Jersey, have invented a new and useful Improvement in Self-@entering Center-Punches and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification, in which- Figurel is a central vertical section Aof a selfcentering center-punch constructed according to my invention. Fig. 2 is a top view of the same. Fig. 3 is a horizontal section of the same.

Similar letters of reference indicate corresponding parts in the several figures.

This invention relates to the arrangement of a center-punch in a guidesocket, which is so applied, in combination with a centeringclamp, that on applying said clamp to a shaft, bolt, or other article to be centered, with the clamp open, the punch may be brought to a position concentric with the said article by the closing of the centering-clamp upon the said article.

It consists in the arrangement of the guidesocket which contains the center-punch with in a hinged frame7 so applied, in combination with the box or its equivalent which contains the centering-clamp, as to provide for the insertion within the said clamp of abolt or other article having a head in such manner as to enable the true centering of the head of the said article to be effected.

It also consists in so applying the guide-v socket within the said hinged frame as to provide for its adjustment to suit the thickness or depth of the head of the bolt.

To enable others skilled in the art to make and use my invention, I will proceed to describe its construction and operation.

A is a box of cast-iron or other metal, of oblong quadrangular form, containing the centering-clamp,'whicl1 is fitted to slide rectilinearly between the front and back of the said box. This clamp is composed of two pieces, B and B', and parts of B are fitted to slide in groovesl a a in the sides of B. These pieces B and B i are made with concave-sided V-shaped jaws b b and b b for the reception of the shaft, bolt,

or other article to be centered, which is represented in red color in Figs. l and 3, the inner faces of the two jaws being of corresponding form.4 The piece B is made with a lug, 1'., on its back side, andin this lug there is a hole, in which is cut a right-hand female screwthread. The other piece` B', is made with a similar luO t" in which there is a hole exactlv opposite and in line with that in z', and in this hole there is a left-hand female screw-thread.

In theback part of the box there is arranged in suitable bearings, parallel with the sliding movement of the jaws, a shaft, C, in the exterior of which there'is a right-hand screwthread, c, which works in the tapped hole of the lug t', and a left-hand screw-thread, c', which works in the tapped hole of the lug i', and this screw-shaft is furnished outside of the box with a hand-crank or handle, D, by which to turn it, for the purpose of producing alongitudinal movement of the jaws toward and from the center of the box for the purpose of grasping a shaft, bolt, or other article inserted' axis of the punch E, which is fitted to slide longitudinally in the guide-socket F, arranged on the top of the box.

G is the hinged frame, which holds the guidesocket F. This frame is hinged at its back, as shown at mm, to a plate, H,which is firmly secured to the top of the box A by screws e c. The guide-socket F is secured by a set-screw, f, in a second socket, g, provided for its reception in the hinged frame G. .The said hinged frame is so constructed that it may come to a firm bearing on the top of the plate H, with the axis of the punch directly in line with the axis of a shaft, bolt, or other article held between the centering-jaws b b, as shown in Fig. 1, and a hole is provided in one side of the said frame for the purpose, when it is in this position, of receivingV the end of a setscrew, I, which screws through a vertical projeeti'on on one side of the plate H, the said set-screw serving to secure the said frame and keep the fsocket-guide in proper position for the operation of the punch. In the upper part of the guide-socket there is a vertical slot, y', through which a pin, k, is screwed, or otherwise tightlyinserted into a hole in the punch. rIhis pin serves to prevent the punch from dropping out when'the hinged frame is turned back, as will be presently described, or when the whole apparatus is thrown aside carelessly on a bench. The plate II has provided in it a hole, Z. opposite the hole d, for the punch to pass through, or for the passage of a bolt or other article through it from the upper side.

For centering shaft-ing or other articles which have not heads larger than the other parts, the frame G is kept secured by the setscrew I in the position represented, with the punch perpendicular to the sliding movement of the jaws B B, and the box, with the centering-jaws open, is placed over the end of the shaft or other article, which passes through the opening 71I in the bottom of the box A and between the centering -jaws rIhe ja-ws are then closed tightly upon the said article by turning the crank I) and screw-shaft (l, and the punch thus brought exactly opposite the true center. The punch is then struck on the head with a hammer, and the centering ofthe end of the article is effected. rIhe -jaws are afterward sl ack cned by turning back the screw shaft.l and theI box removed and applied to the other end ofthe shaft or other article, which is then treated in like manner. The centering operation may be performed while the sha-ft or other article is in a vertical, horizontal, or any other position.

For centering a bolt or other article having a head larger than the other part, such as shown in red outline in Fig. l, the set-screwI is unscrewed, and the frame G, with the contained guide-socket and punch, turned back on the hinge m far enough t0 permit the smaller part of the article to be inserted through the holes Z and d and between the centering-jaws. The head is allowed to rest upon the plate H. The set-screw f is then unscrewed to liberate the guide-socket, and the frame G brought forward to the position shown in Fig. l, and theI set-screw Iscrewed up to secure it. The guidesocket F is next adjusted in the outer socket, g, to the proper distance from the top of the article to be centered, and secured by the setscrew f, and the head of the punch then struck with a hammer to effect the centering.

v For centering t-he heads of a number of bol is or other articles havingheads of uniform thickness, but one adjustment of the socket F in the socket r/ is required 5 but the hinged frame G requires to be turned back after each centering operation to allow the centered article to be taken out.

I do not claim of themselves the two centering-jaws operated by a right and left handed screw, as I am aware that such jaws so operated have been used in a drilling-machine; but

IVhat I claim as my invention, and desire to secure by Letters Patent, is-

l. The arrangement of the guide-socket F, which contains the center punch within a hinged frame, G, appliedin combination with the box or its yequivalent which contains the centering-clamp, substantially as and for the purpose herein set forth.

The arrangement of the guide-socket within the said hinged frame to provide for its adjustment, substantially as herein described, to suit the thickness or depth of the head of a bolt or other headed article.

SAML. Z'. HALL.

fitnessesr M. A.. Geminis', M. E. Annnnws. 

